package com.ryl;

/**
 * @Date 9:48
 * @Author ryl
 */

public class Demo2 {
    B b=new C();
    C c= (C) new B();
    C c1= (C) b;
}
abstract class A{
    public abstract void test();
}
class B extends A{

    @Override
    public void test() {
        
    }
}
class C extends B{

}
